But in this case, it is. Move over Pluto… you’re no longer the only game in town when it comes to recent moon-spottings.

Earlier this week, researchers at the SETI Institute and NASA announced the discovery of a new moon for the ice giant planet Neptune. The discovery was made by researcher Mark Showalter of the SETI Institute while studying the tenuous arcs of Neptune’s rings.

The initial images analysed for the discovery were taken from the Hubble Space Telescope and span a period from 2004 to 2009 in which the diminutive moon, tentatively dubbed S/2004 N1 shows up in 150 frames. This enabled Showalter to cinch its orbital period of 22.5 hours. At 18 kilometres across, S/2004 N1 is the smallest of the Neptunian family of satellites, and brings the count for the planet up to 14 moons.

“The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system,” Showalter said. “It’s the same reason a sports photographer tracks a running athlete – the athlete stays in focus, but the background moves.”

The tiny moon orbits only 105,283 kilometres distant from Neptune, 25% of the Earth-Moon distance and 6th in order for Neptune’s retinue of moons. At 18 km in size, it would fit inside Florida’s Tampa Bay. The moon is extremely faint as seen from the Earth at magnitude +26.5, 100 million times fainter than the faintest stars visible to the naked eye.

Contact and capture of the Hubble Space Telescope during the final repair mission, STS-125. Credit NASA

The space shuttle Atlantis also played a key role in the follow up for this discovery. On mission STS-125 in May 2009, astronauts visited the Hubble Space Telescope one last time. Spacewalking Astros Andrew Feustel and John Grunsfeld installed the Wide Field Camera 3 that would eventually allow Hubble to make the follow-up confirmation observations of Neptune’s new moon, featured at the intro of the story.

To date, Voyager 2 stands as the only mission that has given us close up views of Neptune, when it conducted a brief flyby 5,000 kilometres above Neptune’s cloud tops on August 25th, 1989. Voyager 2 discovered 5 new moons, later named Naiad, Thalassa, Despina, Galatea and Proteus. It’s interesting to note that it missed tiny S/2004 N1.

Neptune was the first planet discovered by a deliberate systematic search in 1846, and the first Neptunian moon discovered was Triton spotted by William Lassell on October 10th, 1846, just 17 days after the planet itself was found. Neptune will reach a favorable opposition next month on August 27th, and its largest moon, Triton, is just within reach of a large backyard telescope.

Neptune and its large moon Triton as imaged by Voyager 2 during its 1989 flyby. Credit NASA/JPL

If the recent controversy of naming Pluto’s new moons is any indication, naming S/2004 N1 may be an interesting affair. Current convention has the large moons of Neptune assigned names of characters from Roman or Greek mythology associated with Neptune or Poseidon. Irregular satellites, such as S/2004 N1 are named after the Nereids, which are the daughters of Doris & Nereus in mythology. Thus, “Vulcan” is probably out (Sorry, William Shatner).

Congrats to Showalter and team on their latest discovery. This just goes to show that there’s lots more of our very own solar system to explore out there. Hey, its even worth culling through old archival data-just a few years back, a desktop sleuth noticed a shadow transit of the tiny Neptunian moon Despina in the Voyager 2 images that researchers missed!

A dedicated probe orbiting Uranus or Neptune would turn undoubtedly turn up some new moons as well. Of course, such an effort would be a decade long affair- New Horizons, launched in 2006 and speeding along at 15 km per second, will only cross the orbit of Neptune next year, and pass Pluto in July 2015… standby for a bonanza of planetary science and new surface features (and just perhaps more moons) as yet to be named.

Science journalist, astronomy specialist, educator. Retired from the USAF in 2007 and am now a science teacher and freelance science writer. Am out stargazing on every clear night and hope to add science... read more fiction writer to my resume!View author's profile